Dowry mainly helps to give a start to life fulfilling basic needs of daily living for newly married couple in ancient time ,
To support their own new family ancient Sri Lankan used give something for them. So dowry's main idea was to give an initial support to newly married couple to start a life.., but later on it changed to something groom's family is expecting to have something for him to marry a bride.., this depend on the culture.. Other Asian countries are expect dowry from man.
Anyway dowry is not valid anymore guys